ITEM 602  MASONRY

602.01   Description
602.02   Materials
602.03   Construction Requirements
602.04   Method of Measurement
602.05   Basis of Payment

602.01 Description.  This work consists of constructing headwalls, pipe cradles, collars, and other brick and masonry units of the types and sizes specified.

Use all suitable material in the work.  Alternatively legally use, recycle, or dispose of all excavated materials according to 105.16 and 105.17.

602.02 Materials.  Furnish materials conforming to:

602.03 Construction Requirements.  Construct the designated items as shown on the plans.

Take adequate precautions to prevent concrete and mortar from freezing.  Do not set brick and masonry units having a temperature of 40 °F (4 °C) or less with mortar until heated.  When required, heat to ensure that a temperature of 50 to 80 °F (10 to 27 °C) is obtained throughout the entire mass of the material.  Lay the bricks masonry units with full mortar joints.  Cure the exposed surfaces of all brick and block masonry by covering with wet burlap for 48 hours or by applying curing membrane according to Item 511.

Excavate to dimensions that provide ample room for construction.  For precast structure headwalls for pipes, slab footers, and cut-off walls, extend the excavation down 6 inches (150 mm) beyond the required bottom elevation and provide a granular base.  Remove obstructions as necessary to perform this work.

Protect the sides of all excavations from caving by providing suitable sheeting, shoring, and bracing.  Use excavation methods that do not disturb the original material below the bottom of footers or below the additional 6 inches (150 mm) required for precast structures.

If the material found at the bottom of the headwall or below the additional 6 inches (150 mm) required for precast structures is not suitable for a foundation, excavate to further depth to provide a suitable foundation.  Backfill the void left by the additional excavation with granular base.  The Department will pay for this additional work according to 109.05.

Backfilling shall follow completion of the work as closely as the construction will allow.  Place the soil around the work to completion.

Place the granular base or soil in 6-inch (150 mm) loose lifts.  Compact according to Item 203 except for the following:

A.     Use 95 percent compaction for acceptance.
B.      Use a minimum of four passes per lift.
C.     Use compaction equipment with a minimum total weight of or minimum centrifugal force of 1 ton (0.9 metric ton).  Supply the manufacture’s specifications for this equipment to verify these requirements.

Construct concrete headwalls, concrete cradles, and other concrete masonry using methods specified in Items 499, 511, and 509.

When using precast structures, conform to the following:

A.     Use headwalls for pipes, slab footers, cut off walls, headwalls for boxes, headwall for three-sided culverts, and wingwalls that conform to the pre-approved design approved by the Office of Structural Engineering and on file with the Office of Material Management.
B.      Construct precast structures using the methods and materials specified in the pre-approved design.
C.     Ensure that non-approved manufacturers submit their structural design criteria, analysis method, and structure details for approval.  Ensure that approved manufacturers submit changes to their approved designs for approval.
D.     Fill the void between the precast pipe headwall and the conduit by using nonshrink mortar.
E.      The manufacturer of precast structure items must be certified according to Supplement 1073.

Construct block or brick walls to the thickness shown on the plans.  Thoroughly wet blocks or bricks before laying the mortar.  Lay the bricks with full mortar joints.  Use one of the following mortar compositions:

A.     One part portland cement to two parts sand by volume.  The Contractor may add lime in an amount not to exceed 10 percent of the cement by weight.
B.      One part masonry cement to two parts sand by volume.

602.04 Method of Measurement.  The Department will measure Brick Masonry, Block Masonry, and Concrete Masonry by the number of cubic yards (cubic meters) calculated from dimensions shown on the plans.

602.05 Basis of Payment.  When a precast structure is used, payment is based on the number of cubic yards (cubic meters) required for the cast in place item and is considered full compensation for construction of the precast structure.

The Department will pay for accepted quantities at the contract prices as follows: